Honeywell International Inc.

David S Willits

Paul S Fechner

Donald Horkheimer

Timothy J Hanson

Terrance Troske

Embodiments described herein provide for a pH sensor that comprises a substrate and an ion sensitive field effect transistor (ISFET) die. The ISFET die includes an ion sensing part that is configured to be exposed to a medium such that it outputs a signal related to the pH level of the medium. The ISFET die is bonded to the substrate with at least one composition of bonding agent material disposed between the ISFET die and the substrate. One or more strips of the at least one composition of bonding agent material is disposed between the substrate and the ISFET die in a first pattern.

ph sensor with bonding agent disposed in a pattern

Embodiments described herein provide for a pH sensor that is configured for use over a pressure and temperature range. The ISFET die of the pH sensor is bonded to the substrate of the pH sensor with a bonding layer that is disposed between the substrate and the ISFET die. The pressure and temperature change across the pressure and temperature range generates an environmental force in the pH sensor. Further, the substrate or the bonding layer or both change volume over the pressure and temperature range, and the substrate or the bonding layer or both are configured such that the volume change induces a counteracting force that opposes at least a portion of the environmental force. The counteracting force is configured to maintain the change in piezoresistance of the ISFET die from the drain to the source to less than 0.5% over the pressure and temperature range.

pH sensor with substrate or bonding layer configured to maintain piezoresistance of the ISFET die

One embodiment is directed towards an inertial measurement unit (IMU) for measuring an input rate of rotation about an input axis. The IMU includes a first three dimensional gyroscope disposed such that a first axis of its three axes is oriented at a skew angle in degrees away from a reference plane, wherein the reference plane is normal to the input axis. The IMU also includes one or more processing devices coupled to the first gyroscope. The IMU also includes one or more data storage devices coupled to the one or more processing devices, the one or more data storage devices including instructions which, when executed by the one or more processing devices, cause the one or more processing devices to calculate the input rate of rotation based on dividing a sensed rate of rotation about the first axis by the sine of the skew angle.

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Long Lake, MN, United States of America

David S Willits